Tradução, adaptação transcultural e validação do Spine Functional Index para o português brasileiro

Abstract

Objective: To translate, cross-culturally adapt and validate the SFI into Brazilian Portuguese in individuals with musculoskeletal disorders of the spine. Materials

and Methods: The SFI was translated and cross-culturally adapted, and the pre- final version was applied to 30 individuals with musculoskeletal disorders of the

spine and who reported pain. The final version of the SFI was applied to 194 individuals to verify structural validity. Construct validity was observed using Spearman correlation (rho) with the following instruments: Roland Morris Disability Questionnaire for general pain, 36-item Short Form Health Survey (SF-36) and Numerical Pain Scale (END). The internal structure of the SFI was evaluated by confirmatory factor analysis with chi-square fit indexes divided by degrees of freedom (X2/gl), Root Mean Square Error of Approximation (RMSEA), Comparative Fit Index (CFI) and Tucker Lewis Index (TLI). A subsample of 43 individuals completed the SFI at two different times, to assess the test-retest reliability using the intraclass correlation coefficient (ICC), measurement standard error (MPE) and minimum detectable difference (DMD). Internal consistency was tested using Cronbach's alpha (α). The ceiling and floor effects were also evaluated. Results: In the process of translation and cross-cultural adaptation, no item in the pre-final version of the SFI presented comprehension problems for more than 20% of the individuals, resulting in the final version. Factor analysis identified a unidimensional SFI structure with acceptable fit indices (X2/gl = 1.88, RMSEA = 0.068, CFI = 0.959, TLI = 0.947). The SFI demonstrated good reliability (ICC = 0.826) and internal consistency (α = 0.864). The EPM was 9.08 and the DMD was 25.15. The SFI also showed a high correlation with the QIRM-g (rho = -0.777) and with the functional capacity domain of the SF-36 (rho = 0.718). There were no ceiling and floor effects. Conclusion: The SFI translated and cross-culturally adapted into Brazilian Portuguese has adequate reliability, internal consistency and construct validity, in addition to a unidimensional structure.